#### Molar Mass, Molecular Weight and Elemental Composition Calculator

Molar mass of KI is 166.00277 ± 0.00013 g/mol
Compound name is potassium iodide

Convert between KI weight and moles
CompoundMolesWeight, g
KI

Elemental composition of KI
ElementSymbolAtomic weightAtomsMass percent
PotassiumK39.0983123.5528
IodineI126.90447176.4472

Mass percent compositionAtomic percent composition

Sample reactions for KI
EquationReaction type
Pb(NO3)2 + KI = PbI2 + KNO3double replacement
KI + Cl2 = KCl + I2single replacement
Br2 + KI = KBr + I2single replacement
AgNO3 + KI = AgI + KNO3double replacement
KI + CI2 = KCI + I2double replacement

Formula in Hill system is IK

### Computing molar mass (molar weight)

To calculate molar mass of a chemical compound enter its formula and click 'Compute'. In chemical formula you may use:
• Any chemical element. Capitalize the first letter in chemical symbol and use lower case for the remaining letters: Ca, Fe, Mg, Mn, S, O, H, C, N, Na, K, Cl, Al.
• Functional groups: D, Ph, Me, Et, Bu, AcAc, For, Ts, Tos, Bz, TMS, tBu, Bzl, Bn, Dmg
• parantesis () or brackets [].
• Common compound names.
Examples of molar mass computations: NaCl, Ca(OH)2, K4[Fe(CN)6], CuSO4*5H2O, water, nitric acid, potassium permanganate, ethanol, fructose.

Molar mass calculator also displays common compound name, Hill formula, elemental composition, mass percent composition, atomic percent compositions and allows to convert from weight to number of moles and vice versa.

### Computing molecular weight (molecular mass)

To calculate molecular weight of a chemical compound enter it's formula, specify its isotope mass number after each element in square brackets.
Examples of molecular weight computations: C[14]O[16]2, S[34]O[16]2.

### Definitions of molecular mass, molecular weight, molar mass and molar weight

• Molecular mass (molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). (1 u is equal to 1/12 the mass of one atom of carbon-12)
• Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol.
Weights of atoms and isotopes are from NIST article.

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